Known in this context from “Ability of Aerosols to Penetrate Paranasal Sinuses” H. Kauff. Archive. klin. Exper. Ohren-,Nasen- and Kehlkopfheilk. 190, 95-108 (1968) is that pressure fluctuations and vibrations can cause aerosols to penetrate the paranasal sinuses through which the main aerosol flow through the nasal cavities does not actively flow. An example of the application of these findings is known from EP 0 507 707 A1. According to this, an aerosol flow is superimposed with pressure fluctuations which are intended to cause the aerosol particles/droplets in the main aerosol flow to pass through the ostia and enter the paranasal sinuses.
In this way, although the main aerosol flow does not directly flow through the paranasal sinuses, they can be reached and treated by a drug administered in aerosol form. As with other types of aerosol therapy, it is attempted to deposit sufficient quantities of the drug at the desired points, for which in the case of the paranasal sinuses a sufficient quantity of the aerosol in the main aerosol flow must pass through the ostia and penetrate the paranasal sinuses.
Experimental investigations on different models of human nose have demonstrated that when known therapeutic aerosol devices are used deposition in the paranasal sinuses is less than expected and desired. The opening size of the ostia, which due to the disease is often extremely small, also has a greater influence on deposition than generally assumed.